Process of reacting 1-alkene hydrocarbons with an ester typified by diethyl dichloromalonate



Patented Dec. 4, 1951 ritoeEssoFnEAo'rnyG l-ALKIlNE HYDRO- 'GARBONS WITHAN ESTER TYPIFIEDBY DI'ETHYL DIGHLOROMALO NA TE 1 Elbert C. Ladd, Passaic, NsJ, assignor to United States-Rubber fi m ny, 1 .QQI'DNQMQQILDQLNQVE er ey I a No Drawin grbflpplication May 27,1949, I ""'.Sei1ialN0.95,882

: cam. (01. 2605-483) j This invention relates to .newlchez izicals .alnd-to u .a .new method for their synthesis. More lspecifi: 31157 .myd-iscoveryeoncerns the-reaction ofester of dihalogenomalonic acid or of alphaalphaedi .halogenoacetoa-eetic acid or-the like-with mono- 1 olefinic .l-alkene hydrocarbons in .thepresenoe of ya source of free radicals. :My invention can be malonate with ethylene:

illustrated .by the reaction of :diethyl dichlor Where n is aninteger, -ovf.ofrom,1 .to.3v and prefer ably is 1. My mventionlcanfalsq-be illustrated by the reaction of ethyl alpha,alpha-dich1oroacetoacetate with ethylene: V y

d .It is known that. .aicmmlmacidfs teis react with olefin hydrocarbons in the presence of free radicals thusz V J 1 1 tree ohoH-oo-oom, ncm=ou radicals 02350-1: o .-o 11, am-011, 41

:However, as 1 shown 'in'reaction' 13) if there'iis 1a ;hy dro'gen atom iattachedeto :the alpha carbon atom bearing the chlorine substituentspsaid hy drogen atom ..is-.the labile,tir.eactive atom; and the two chlorineatoms fia-re virtually-inactive; "Hence .not only zare-lowsyieldsof product-ob tained, :bu't ithe reaction :alsoileads to "the formation of mixtures of higher molecular weight materials in which n is greaterthan 5, particularly where readily polymerizable olefins are used, and very little of the produets-in'which n is from 1 to 3, can be economically obtained. Furthermore, the products from the adichloroacetate are not analogous to those made by therresen 111K613: t n ecause, in theiormer the alkylene chai d rived iron; the olefin do s .not have a-terml na halogen atom remoteimm the-earboxylic time:

the molecule. .I Tl

are oor; and little; if any, of those if the dichlorinated alpha-carbon atoin bears an alkylsubstituent in place of hydrog'emthe alpha- "halogen atoms do participate the reaction. 'HoweverjIfhave found that "the reactivity'ofisuch compounds, which have only-one carbonyl group linked to the alpha carbon atom, is 1ow,"an'd becomes even lower as the length of the hydrocarbonfl-substituent is increased; again, the yields adducts wherein'n is from'l to 3a-re obtained. I Ihave now discovered"that if an alpha.alphadihalogenoalkanoate contains as the third substituent on the alpha carbon atom another group linked through carbonyl, the reactivityFoi' the compound towards 1-alkene hydrocarbons is remarkably enhanced, to such an extent "that satisfactory yields of those adducts which n is from to '3, particularly '1, are re'adily' obtained. The' highly reactive compounds which I use areseen to be characterized by the rouping -'CO -'CXzCO-'. One of these carbonyl groups is further linked to alkoxy, and the other to alkyl or alkoxy. 7 The reaction of my invention .can be represented as iollows:

where R is alkyl, X iseither chlorine or. bromine, Y is alkyl (almost invariably methyl) or alkoxy, It and R are either hydrogen or alkyl, .and n is an integerof from 1 to3.

Any dialkyl ester of dichloroor dibrompmalonic acid maybe used in practicing my invention. 'While the alkyl groups are usually identical, they may be different. I usually employ diethyl dichloroor dibromomalonatdh cause of cheapness and readyavailabilityof these comp unds. Oth r exa ples of es ers wh h an be used are the alpha, alpha-dichlqros and alpha,alpha-dibromoderivatives of dimethyl malonate, methyl ethylmalonate, dipropyl malonate, ethyl prop l malonate. d but z maionete Instead of esters of alpha,alphadihalogenoi acetoacetic acid, I may use esters of alpha alphae. dihalogen homologs of acetoacetic acid such asthose wherein the methyl group attached to thebeta-keto carbon atom is replaced by ethyl, pro

pyl, butyl, amyl, hexyl, etc., preference being? 7 given to the lower alkyl groups. alpha-dihalogenoacetoacetic acid are by far pre ferred.

carbon may be used in the practice of my invention. from 2 to 20 carbon atoms per molecule. Examples are ethylene, propylene, 1-butene,'isobutylene, and any of those pentenes, hexenes, heptenes, octenes, nonenes, decenes, dodecenes', etc., having a single terminal ethylenic group.

The reaction of my invention is carried out by heating at a temperature of from 25 to 200 C., preferably from 60 to 120 C., a mixture of the ester of dihalogenomalonic acid, or of alpha, alpha-dihalogenoacetoaceticacid or the like, with the monoolefinic l-alkene hydrocarbon in molar ratios of from 1:10 to 20:1, preferably from 1:1 to 15:1,in the presence of a source of free radicals for reaction times which usually range from; to 50 hours. In the case of the lower l-alkencs which are gaseous at ordinary temperatures or at the reaction temperature, it will usually be preferable to carry out the reaction under superatmospheric pressure sufficient ,to cause the reaction to proceed at a desirable rate.

Suitable promoters formy reaction are'those capable of undergoing thermal decomposition-to yield free radicals, including peroxidic compounds (e. g., hydrogen peroxide, tertiary-butyl hydrogen peroxide, and acyl peroxides such as benzoyl peroxide and acetyl peroxide), metal alkyls (e.-g., sodium ethyl, potassium amyl and lead tetraethyl) and alnha,a1oha-azobis(alphaalkylalkanoic) acids and derivatives hydrolyzable thereto such as the nitrile, ester and amide (e. g., alnhaalphaf-azobisisobutyric acid, a1'oha,alpha'- azobisisobutyronitrile, and alpha,alpha'-'azobis- (alpha-methylbutyronitrile)). Such compounds are usually employed in amounts ranging from 0.1 to about of the weight of the reactants.

At the conclusion of the reaction, the products can be isolated and purified by preferential extraction, fractional distillation or crystallization.

The following examples disclose my invention in more detail.

Example 1 V Example 2 An autoclave of 1.25 liters capacity and con- Esters ofalpha' The hydrocarbon will typically contain V H I :';i chlorobutyl'rf malonate, b. 126-8" Any aliphatic monoolefinic 1-alkene hydroi- 4 taining 1145 g. of diethyl -alpha,alpha-dichloromalonate and 4 g. of benzoyl peroxide is closed and evacuated. Ethylene is then admitted until a pressure of 240 p. s. i. at 70 C. is attained.

,jThe reaction' is carried' out,with agitation, for 21 hours at thistemperature' and pressure, the latter -distilled.g-'Ing= this" manner are obtained three 5153 91458; and (3) a new compound, the 1:3 adduct, believed to be diethyl aloha-chloro-alpha- (6"-chlorohexyl) malonate, b. -7 C./2 mm.

. Th! t u s m nti v n u e. s a

ticlzers for polymeric materialspand as synthetic intermediates which can be'mo'dified by reactions such" as, hydrolysis, dehydrohalogenation. and decarboxylation." i V I -'I-Iavingthus described my inventionfwhatfI claimand desire to protect by Letters Patentis: l. ;The-" process which comprises; reacting a moiioolefinic l-alkene" hydrocarbon with an ester having the formula where R is alkyl, X is fa halogen selected from thclass consisting of chlorine and bromine and Y is selected from the class consisting of alkyl and alkoxyin the presence of free radicals and recovering from the resulting reaction mixture a compound having the formula COOR where R, X and Y areas before and where R where n is an integer of from 1 to 3. v

4. The process which comprises reacting a monoolefinic l-alkene hydrocarbon with ethyl alpha,alpha dichloroacetoacetate inthe presence of free radicals and recovering from the resulting reaction mixture a compound having the formula where R and R" are selected from the class consisting of hydrogen and alkyl, and where n is an integer of from 1 to 3.

5. The process which comprises reacting 1- octene with ethyl alpha,alpha-dichloroacetoacetate in the presence of free radicals and recover- Y 6 ing ethyl alpha-chloro-alpha-(Z-chlorooctyl) acetoacetate from the resulting reaction mixture.

- ELBERT C. LADD.

REFERENCES CITED The following references are of record in the file of this patent:

Pesina, Chemical Abstracts 34, columns 425- 426 (1940). 10 Hems, Jour. Chem. Soc. (London) (1944), 626- Adams, Jour. Am. Chem. Soc. 63, 228-236 (1941).

Nicolet et a1., Jour. Am. Chem. Soc. 49, 2066- 16 2071 (1927). 

1. THE PROCESS WHICH COMPRISES REACTING A MONOOLEFINIC 1-ALKENE HYDROCARBON WITH AN ESTER HAVING THE FORMULA 